1. Field of the Invention
The present invention relates to a band pass filter, and more particularly, to a band pass filter constituted by a printed circuit board (PCB) and a multi-layer ceramic chip (MLCC) to be mounted in a circuit, without additional parts such as a low temperature co-fired ceramic (LTCC) based filter, and so on.
2. Description of the Related Art
In general, filters may be classified into an LTCC based filter, a PCB or MLCC filter, or a filter in which an inductor and a capacitor are coupled to each other.
The LTCC filter, which is a filter implemented using a multi-layer ceramic substrate, has a large tolerance to decrease productivity. In addition, the LTCC filter is formed of a fragile material to decrease reliability and increase production cost, and its design is very difficult and its pass band is fixed.
The PCB filter, which is a filter implemented by only a PCB pattern, generally has a large size varied according to a frequency, and a pass band according to design thereof is fixed.
Specific design of the filter in which the inductor and the capacitor are coupled to each other is difficult due to limitation in device value, and performance of the filter may be decreased due to a low Q value of the inductor.